refactoring the naming mtx to be mtx_
refactoring the naming mtx to be mtx_

yungyuc/solvcon,solvcon/solvcon,solvcon/solvcon,yungyuc/solvcon,yungyuc/solvcon,yungyuc/solvcon,yungyuc/solvcon,solvcon/solvcon,yungyuc/solvcon,solvcon/solvcon,solvcon/solvcon,solvcon/solvcon